Photographic apparatus for spreading a fluid between superposed sheets



Oct. 7; 1958 D R. BISHOP 2,854,904

PHOTOGRAPHIC APPARATUS FOR SPREADING A FLUID BETWEEN SUPERPOSED SHEETS 2 Sheets-Sheet 1 Filed Dec. 2, 1955 66 74 8 0 86 ea 64 70 8 e 4 I ea as 34 [e I X /8 f 80 86 8 64 s /t 70 88 E6 Oct. 7, 1958 D. R. BISHOP 2,854,904 PHOTOGRAPHIC AP RA F0 PREADING v A FLUID BETW SU POS SHEETS Filid D90. 2, 1955 r 2 Sheets-Sheet 2 United States Patent ce PHOTOGRAPHIC APPARATUS FOR SPREADING A FLUID BETWEEN SUPERPOSED SHEETS Donald R. Bishop, Westwood, Mass, assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware Application December 2, 1955, Serial No. 550,703 13 Claims. (Cl. 95-13) This invention relates to photography and more .particularly to apparatus for distributing a processing liquid between two layers of photographic material.

It has been proposed to process photographic sheet material, and preferably an exposed photosensitive sheet, by spreading a processing liquid in a layer between the photosensitive sheet and another sheet. The processing liquid is spread between the sheets in a uniform layer of predetermined thickness by advancing the sheets through a gap or throat formed by two substantially parallel rigid members predeterminedly spaced apart and so constructed as to cause hydraulic pressure to be generated in the liquid between the sheets to spread said liquid in a layer therebetween during movement of the sheets through the gap between said rigid members. U. S. PatentNo. 2,483,014, issued September 27, 1949, in the name of Edwin H. Land et al., discloses apparams of this type and defines certain relationships existing between the relative thicknesses of the sheet materials and the layer of liquid and the width of the pressure-gencrating throat, the viscosity of the liquid, the rate at which the liquid is drawn through the throat, the shape of the members defining the throat and the pressure generated within the liquid; and how these relationships may be so controlled as to insure the spread of the liquid over a-given area in a layer of substantially uniform predetermined thickness regardless of variations in the thickness of the sheet material, the viscosity of the liquid and the speed of movement of the sheet material through the throat.

A liquid-spreading device of this type offers the advantages of simple and inexpensive construction, together with dependable and consistent operation resulting in the spreading of a liquid in a uniform layer of predetermined thickness, and is particularly adapted for use in association with photographic apparatus such as a camera wherein a photosensitive sheet is exposed and thereafter processed in conjunction with a second sheet by a layer of liquid distributed between the sheets. The spreading device is preferably so mounted on a camera that the exposed photosensitive and other sheets are superposed and drawn through the spreading gap during withdrawal of the sheets from the camera. Two members comprising the gap exert pressure in opposite directions substantially in a plane and the aforementioned relationships are fully applicable to insure spreading of the liquid only when the sheet materials are moved through this gap in another plane substantially perpendicular to the first-mentioned plane. However, withdrawal of. sheet material from the camera through the gap or slot is usually performed manually, the operator grasping the camera or spreading device with one hand and the sheet material with the other hand so that there can be no absolute control on the direction of tension on the sheets and they .are not certain to be withdrawn from the camera through v the gap in the desired plane, but may be withdrawn in a plane at an angle with respect to the desired plane.

'This deviation from the desired plane during movement 2,854,904 Patented Oct. 7, 1958 of the sheets through the gap results in lack of uniformity of the thickness of the layer of liquid spread between the sheets depending on the angle of deviation.

Accordingly, it is one object of the present invention to provide a simple and inexpensive device including a substantially fixed gap or throat for distributing a liquid in a uniform layer of predetermined thickness between two layers of sheet material moved through said gap, said device including means for guiding said sheet material through said gap in a predetermined plane.

Other objects of the invention are: to provide a fixed gap spreading device of the above type as an element of a film unit comprising a photosensitive sheet and a second sheet superposable with the photosensitive sheet, the spreading device being capable of being releasably secured to apparatus for photoexposing said photosensitive sheet; and to provide a fixed gap spreading device of the above type mounted on photographic apparatus such as a camera with the members thereof defining said gap being movable with respect to one another to permit the movement of a film unit between said members with out the application of pressure on said film unit.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the follow: ing detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

Figure 1 is a perspective view of a device for spreading a liquid in a layer between two layers of sheet material;

Fig. 2 is an exploded perspective view of another form of liquid-spreading device;

Fig. 3 is a sectional view of a film unit of the invention taken substantially midway between the sides of the film unit and embodying the liquid-spreading device of Fig. 2;

Fig. 4 is a perspective view, partially in section, of a typical camera adapted to use with the liquid-spreading device of the invention; and q Fig. 5 is a fragmentary perspective view, partially in section, of a camera embodying another form of liquid spreading device. I

The spreading of a fluid composition in a uniformly thin layer between a pair of superposed sheets may be employed for effecting a number of various photographic processes and is particularly adapted, for example, to the processing of an exposed photosensitive stratum on one of the sheets to develop a latent image in the photosensitive stratum and/or produce a positive image in the other sheet by diffusion and transfer of reagents from the photosensitive stratum through or into the fluid layer. The present invention is concerned with the provision of a spreading device adapted to be employed, for example, with a film unit comprising a first sheet having a photosensitive surface stratum and a second sheet superposed with the first sheet and having a surface stratum disposed adjacent the photosensitive stratum and adapted to receive a positive photographic image. The spread ing device combines the advantages of accurate control of the fluid spread with a relatively simple and inexpensive construction, since essentially it comprises only two easily formed, rigid pressure members located in parallel relation to provide a gap or slot through which the film unit is moved, and may be provided either as an element of the film unit itself, disposable following processing of'the film unit, or as a component of the photographic apparatus, such as a camera, for differentially exposing the photosensitive stratum of the film unit.

The processing liquid may be supplied in a container interposed between the two sheets of the film unit and adapted to be moved through the gap between the pressure members so as to rupture the container and distribute its contents between the sheets. Since the pressure mem-' bers are substantially fixed with respect to one another, it is important that the film unit comprising two sheets and a container be of substantially uniform overall thickness in the vicinity of at least the container and the layer of liquid distributed therefrom between the sheets. One form of film unit of this type is disclosed in application Serial No. 429,185, filed May 12, 1954, in the name of Edwin H. Land et al., and comprises two sheets, a photosensitive sheet and a second sheet with portions of the two sheets secured together to define a liquid-carrying cavity. Alternatively, the processing liquid may be supplied, as disclosed in the copending application of Edwin H. Land, Serial No. 522,605, filed July 18, 1955, in a container adapted to be removed from the film unit prior to movement thereof between the pressure members and to discharge its contents between the sheets during removal from the film unit so that spreading of the liquid between the sheets is accomplished in the absence of the container. In the form of film unit illustrated in the accompanying drawings, uniformity of thickness is achieved by controlling the relative thicknesses of the sheets in the region of the container and in the region of the layer of liquid between the sheets.

A film unit adapted for use in the present invention is illustrated at 10 in Fig. 3 and comprises a pair of sheets 12 and 14, substantially coextensive with one another and disposed in superposed relation with their inner surfaces in contiguous relation, and an elongated container 16 carrying a predetermined quantity of a processing liquid. Each of sheets 12 and 14 comprises two sections, sheet 12 comprising sections 18 and 20 and sheet 14 comprising sections 22 and 24. Sections 20 and 24 are formed of a material which is substantially thicker than the material comprising sections 18 and 22 and are joined to the latter sections by scarf joints 26 and 28 formed by chamfering the edges of the sections and cementing them together at their chamfered edges. The chamfered edges of sections 12 and 22 forming scarf joints 26 and 28 are tapered toward their outer surfaces and are secured to the chamfered edges of sections 20 and 24 with the outer surfaces of the sections of each pair of sections flush with one another so as to present a substantially smooth continuous outer surface at each joint adapted to pass freely through a snagged or caught by the pressure-applying members forming said gap. The container 16 comprises an elongated strip of sheet material, which is at least impervious to the processing liquid, folded upon itself and sealed together at its edges to provide an elongated cavity extending substantially from side to side of sheets 12 and 14 and carrying the processing liquid. The longitudinal edge seal of container 16 is weaker than the end seals so that the container becomes unsealed along its longitudinal edge in response to the application of compressive pressure to the walls of the container. Container 16 is positioned between sections 18 and 22 of, respectively, sheets 12 and 14 adjacent sections 20 and 24 and with its longitudinal sealed edge located adjacent sections 20 and 24 so that the contents of the container are discharged for spreading therebetween. The liquid contents of the container are preferably quite viscous, having a viscosity, for example, of from 100 to 200,000 centipoises at a temperature of 20 C. for not only insuring a substantially complete rupture of the longitudinal seal of container 16, but for aiding in the formation of a layer of the liquid between the inner surfaces of the two sheets.

The inner surface of section 20 comprises a photosensitive material such as a silver salt and the liquid incorporates a developing agent capable of forming a visible fixed spreading gap without being image in a layer of photosensitive material differentially exposed to actinic light. In a preferred form of film unit, the inner surface of section 20 is coated with a silver halide stratum, section 24 of sheet 14 is coated with a silver precipitating stratum and the processing liquid contains, in addition to a silver halide developer, a silver complexing agent for effecting silver transfer as well as silver reduction. When the liquid is spread between sections 20 and 24, exposed silver halide is reduced to silver and unexposed silver halide forms a complex silver salt which diffuses to the silver precipitating stratum where it forms a positive print.

Film unit 10 is preferably provided with sheets 12 and 14 in superposed relation with sections 18 and 22 secured together to form a leader and sections 20 and 24 secured together at their margins by an adhesive or cement which permits their being stripped apart so that the photosensitive material of section 20 may be exposed. To prevent exposure of the photosensitive material, at least sections 20 and 24 are formed of a material opaque to actinic light or their outer surfaces are provided with a suitable lightopaque coating. This type of film unit is adapted to be withdrawn into the light after spreading of the processing liquid during the processing period and the processing liquid, being viscous, serves to bond sections 20 and 24 together in superposed relation. To prevent the admission of light between sections 20 and 24 through the layer of liquid during processing, the liquid may contain a suitable dye or other material which is opaque to actinic light and does not interfere with the processing.

The spreading gap or throat may comprise, in its simplest form shown in Fig. 1, a rigid plate 30 having an elongated slot 32 formed therein through which a film unit comprising sheets 12 and 14 may be drawn for spreading the processing liquid between the sheets. The edges of plate 30, which define the sides of slot 32 and contact the film unit, are substantially parallel and are preferably shaped to form a convergent entrance throat. The sheets comprising the film unit conform to the shape of this throat as they are moved therethrough, causing pressure to be built up in a liquid between the sheets and this pressure thus generated within the liquid results in distribution of the liquid between the sheets in a uniform layer of predetermined thickness.

The principles set forth in the aforementioned Patent No. 2,483,014 may be applied to the formation and width of slot 32, the thicknesses of the materials and the viscosity of the liquid so that variation in the thickness of either or both of the sheets comprising the film unit will cause only minor variations which are within acceptable limits in the thickness of the liquid layer. However, it has been found that proper operation of a fixed gap spreader based on these principles is dependent on the withdrawal of the sheet material through the gap or slot substantially in an optimum plane which is parallel to the axis of the slot or, in other words, perpendicular to the plane of plate 30 or the plane in which pressure is exerted by the sides of the slot on the sheets. When the path of movement of the sheets deviates from this optimum plane, the sheets are curved or bent around one of the exit edges of the slot, causing a back pressure to be generated within the liquid which resists passage of the liquid between the sheets through the slot and results in either uncontrolled variation in the thickness of the layer of liquid or in spreading of no liquid at all between the sheets.

While somewhat improved spreading characteristics can be achieved by shaping the walls of the slot to form a divergent exit throat to reduce the sharpness of the bend of the sheets when they are moved in a plane other aforementioned optimum plane, uniform spreading of the processing liquid is best assured by moving the sheets through the gap in the aforementioned optimum plane without substantial deviation from said plane. The spreading device of the present invention may comprise either an element of apparatus such as a camera for exposing a photographic film unit or is provided as than an element of the film unit adapted to be secured to the camera when the film unit is positioned for exposure within the camera. A camera of the type useful in association with the present invention is illustrated in Fig. 4 and comprises a housing 34 for mounting and enclosing the components of the camera, a conventional lens and shutter assembly 36 mounted on the forward wall of the housing, a rear wall 38 and a side wall 40 located at an angle with respect to rear wall 38. Rear wall 38 is preferably located at the focal surface of the lens of assembly 36 and a film unit comprising sheets 12 and 14 is positioned with sheet 12 disposed against rear wall 38 with the photosensitive layer thereof located susbtantially at the focal surface of the lens. Guide means may be provided for holding sheet 12 against wall 38. The camera includes an intermediate Wall 44 located adjacent side wall 40 and defining therebetween a chamber 46 for receiving sheet 14 of a film unit during exposure of the photosensitive layer of sheet 12 positioned against rear wall 38. To permit the introduction of a film unit into the camera in such a manner that it is positioned for exposure therewithin, there is provided a narrow elongated passage 48 located in the juncture of walls 38 and 40 and communicating with guide means and chamber 46. The film unit is provided with sheets 12 and 14 secured in superposed relation and passage 48 is adapted to receive the film unit with the sheets so disposed. The sheets may be cemented together around their edges to hold them in superposed relation and a wedge 50 comprising the end portion of intermediate wall 44 is provided in passage 48 for sepparating the two sheets at their leading ends as they are introduced into passage 48 and serves to guide the two sheets into exposure position as shown and described.

The camera is adapted for manual operation so that introduction of the film unit prior to exposure and withdrawal of the film unit after exposure through the spreader gap is effected manually with the operator grasping the camera in one hand and the film unit in the other hand. For this reason, there can be no assurance that the film unit is being moved in a single plane during withdrawal or that this movement is in the aforementioned optimum plane calculated to give the most uniform and satisfactory results. In accordance with the present invention, however, provision is made for guiding the film unit through the spreader gap so that it moves therethrough in the optimum plane regardless of variations in the directionin which the film unit is withdrawn from the camera. Guide members are provided on the exit side of the spreader gap and spaced therefrom so that the film unit is confined to movement in a plane through the spreader gap and for at least a short distance thereafter; and although a curvature or bending may be imparted to the sheets comprising the film unit as they are advanced from engagement with the guide members, such curving or bending does not occur at or closely adjacent the point at which the liquid is spread between the sheets and does not affect the. spreading of the liquid.

These guide members may be provided as elements of the camera and adapted to be spaced apart to permit the introduction of a film unit into the camera, with the liquid-spreading device comprising and expendible element of the film unit adapted to be detachably mounted on the camera. However, it is preferable that the guide members comprise sections of the spreading device and in the form shown in Fig. 1, these guide members comprise dependent sections 52 of plate 30 so constructed as to define a passage or gap 54 spaced from slot 32 and located in a plane through slot 32 perpendicular to plate 30. The width of passage 54 between sections 52 is such that, while pressure is not applied by the sections to the sheets as they move through the passage, substantially no deviation of the sheets from the desired plane of movement is permitted. To prevent sharp bending of the sheets in the event that they are withdrawn from passage r members 64 each including 54 in a plane other than the desired plane, the edges or lips 56 of sections 52 defining the passage are curved outwardly so as to impart a curvature to the sheets which does not have an adverse affect on the layer of processing liquid distributedv between the sheets.

Spreader plate 30 is adapted to be provided as an expendiblecomponent of a film unit and to be removably mounted on the exterior of the camera with slot 32 and passage 54 located in a plane substantially through the center of passage 48 in the camera housing. As a means for mounting spreader plate 30 on the camera housing, plate 30 is provided with dependent end sections 58 extending parallel with one another and adapted to be engaged by suitable mounting means on the camera. For example, end sections 58 may extend between parallel members 59 on the camera housing and may be retained between members 59 by resilient detents 60 adapted to engage portions of sections 58, such as shouldered bosses 61 formed by piercing sections 58.

A more preferred form of liquid-spreading device comprising a component of a photographic film unit and adapted to be operatively mounted on a camera is illustrated in Figs. 2 and 3. This spreading device, designated at 62, comprises a pair of elongated L-shaped a generally flat first section 66 joined to asecond section 68 at a rounded corner section 76 and extending substantially at right angles from section 6.8. Members 64 are secured together with first sections 66 located substantially in the same plane and with corner sections 70 located parallel with one another and predeterminedly spaced apart to form a spreading gap or pressure-generating throat 72 through which sheets 12 and 14 comprising a film unit are moved. The L-shaped construction of members 64 not only provides for ease in fabrication and assemblage of the spreading device but lends rigidity to members 64, especially at rounded corner sections 70, for resisting deformation of said members and subsequent variation in the width of the spreader gap due to pressure generated in the liquid between the sheets moving through said gap. The rounded corner sections 70 provide an accurately formed gap including curved entrance and exit throats having configurations conforming to the aforementioned principles relating to design of fixed gap spreading devices.

Members 64 are mounted at their ends between a pair of L-shaped brackets 74 including first sections 76 extending parallel with one another and adapted to be releasably secured to a camera with the aid, for example, of shouldered bosses 78 formed from sections 76 and adapted to be engaged by detents on a camera. Each bracket 74 includes a second section 80 extending inwardly from sections 76 and divided by a slot 82 into a pair of arms each of which is secured to first section 66 of one of members 64. Members 64 and brackets 74 are preferably formed of substantially rigid sheet material and are secured together, for example, by spot welding. Second sections 63 of members 64 are located adjacent one another and are spaced apart to form the walls of a guide passage 84 which is slightly wider than gap 72 so as not to apply pressure to the sheets comprising a film unit and is located substantially in a plane perpendicular to the plane of first sections 66. Sharp bending of the sheets as they are withdrawn from guide passage 84 is prevented by curving the edges or lips 86 of second sections 68 inwardly so that they impart a uniform curvature to the sheets in the event they are withdrawn from guide passage 84 in a plane other than the plane of said passage.

A film unit including spreading device 62' is provided with sections 13 and 22 of sheets 12 and Mseeured together and extending through gap 72 between members 64 and with sections and it of the sheets in the vicinity of container 16 being located adjacent members 64. To

protect this portion of the film unit including the container.

and to prevent exposure of the from physical damage photosensitive material during withdrawal of the sheets from the camera through gap '72, there is provided a pair of elongated cover elements 83 formed of an opaque and preferably stiff sheet material, such as paper or cardboard, located on opposite sides of sheets 12 and 14 in the vicinity of container 16. Each element 38 is secured along one edge to the first section 66 of a member 64 and at its ends to sections '76 of brackets 74 and with its other longitudinal edge located in contact with one of the sheets comprising the film unit. When the film unit is inserted into the camera, the longitudinal edges of cover elements 83 extend partially into passage 48 into lighttight engagement with the walls of the passage and thus form a lighttight chamber exterior of the camera housing between the latter and members 64-. This lighttight chamber permits withdrawal of the sheets comprising the film unit from the camera and superposition of said sheets with a layer of processing liquid therebetween entirely within a light-free environment, even though superposition and spreading of the processing liquid occurs outside of the camera housing.

A fixed gap spreading device, designated at 98 and comprising a component of a camera, is illustrated in Fig. of the drawings and includes a pair of. combination pressure and guide members 92 and a frame 94 for mounting members 92 on housing 34 of the camera. Frame 94 comprises a forward wall 95, a rear wall 93 and side walls it? defining an open-ended chamber 1 52 and secured to camera housing 34 adjacent passage 48- so that the passage opens into chamber 102. Members 92 are generally elongated and V-shaped in cross section, each member comprising a first section 15M and a second section 166 joined at a rounded corner section 103. Each member 92 is pivotally mounted between side walls of frame 94 adjacent the open end of chamber 162 and for this purpose first section 1% includes a rolled or cylindrical portion lit? disposed around an elongated pivot pin 112 mounted at its ends in side walls lit-ll.

Pivot pins 112 are so mounted and positioned adjacent forward wall 96 and rear wall fit that members 92. are pivotaole to an operative position in closing relation to chamber M2 at which corner sections 1G8 are located parallel with one another and predeterminedly spaced a art to provide a spreading gap or pressure-generating throat 114 through which a film unit may be moved for spreading a processing liquid. In this operative position, second sections of members 9?; are located adjacent one another and are spaced apart to define the walls of a guide passage .11 5 having a width sufficiently g eater than gap 114 to insure that pressure is not exerted on a film unit during movement through passage lid. Members 92 are so constructed and mounted with respect to one another and frame 94 that the centers of passage i116 and gap 11-: are located substantially in a single plane through passage 45 and perpendicular to the plane in which pressure is applied to film unit moving through gap 114.

Second sections Ebb are provided with divergently curved edges or lips 118 to prevent sharp bending of the sheets comprising a, film unit should the film unit be withdrawn from passage 116 in a plane other than the desired. plane. As a means for accurately locating members 92 in operative position, engagement members (not shown) may be provided on side walls of frame 94 for engaging first sections 1% of members Latch means are provided for holding members 92 in operative position with sections .564 located against the aforementioned engagement members and comprise a pair of resilient latch members 322 formed from opposite lateral edges of second section 1% of one of members 92 and adapted to releasably engage second section the of the other of members 92, when the two members are in operative position. Each latch member 122 includes an inwardly extending reentrant portion 124 for engaging the edge of second section 1% and a manually engageable outwardly inclined ramp portion 126 adapted to c0- 9 g) act with the edge of a second section 1% and deform the latch member during movement of second sections 106 toward one another until reentrant portion 124 is engaged. Ramp portions 126 are manually engageablc for deforming latch members 122 so as to release reentrant portions 124 from engagement with sections 1% to permit said sections to be pivoted apart from operative position. As an additional means for preventing pivotal movement of members 92 from operative position, one of sections tee is provided with a pair of overturned tabs 1 8 at each lateral edge between which latch members 122 on the other of sections 1&6 are engaged.

To permit the introduction of a film unit 10 into the camera through passage t? and the movement of the film unit between members ?2 without the application of pressure on said film unit, members 92 are pivotable outwardly from their operative position and, by virtue of their construction and mounting, one of members 92 may be pivoted rearward through almost to a position adjacent rear wall 98 of frame 94 where it may be retained conveniently and out of the way by suitable means when the camera is not in use. The other of members 92 may be pivoted forward to an out-of-the-way position adjacent forward wall 96 of frame 94 and side wall 49 of housing 34 where it may be retained by means provided for this purpose.

Members 92 are so formed that their lateral edges fit snugly between side walls 1% of frame and forward and rear walls 96 and 93 are so formed that their edges engage cylindrical portions lit? of members 92. All the walls of frame 94 are snugly seated on the camera housing 19 and, by virtue of this arrangement, members Q2, when in closed position with a film unit located therebetween, and frame 94 cooperate to make chamber 132 substantial- 1y lighttight so that the sheets comprising the film unit may be withdrawn from the camera and superposed without danger of exposing the photosensitive material. Suitable light-shielding means or baiiles may be provided in chamber 162 on the walls of frame 9w for preventing the admission of light into chamber 162 around the edges of members 92.

in the operation of a camera including liquid-spreading device fid, members 92 are pivoted apart into inoperative position and a film unit 10 comprising sheets and 14 secured together in superposed relation is introduced between members 2 into passage and moved therethrough with the two sheets being separated and advanced into exposure position. Members 92 are then pivoted together into operative position with the leading end section of the film unit extending through spreading gap 114 and guide passage 136, second sections 1% defining the walls of guide passage iitfi acting to locate the film unit in a proper plane. Following exposure of the photosensitive sheet of the film unit, the leading end portion of the film unit is manually grasped for withdrawing the film unit through the spreader gap to super-pose the photosensitive and second sheets of the film unit and spread a. process ing liquid in a layer therebetween. at the end of a predetermined processing period, the second sheet, preferably carrying a positive photographic print, may be stripped from the photosensitive sheet.

Since certain changes may be made in the above apparatus without dparting from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. Photo-graphic apparatus for exposing and thereafter treating a photo-graphic film unit including a photosensitive sheet, a second sheet superposable with said photosensitive sheet and means containing a processing liquid, said apparatus comprising, in combination, a camera for exposing the photosensitive sheet of a film unit, said camera including a passage through which said film unit may be manually withdrawn following exposure therewithin and means mounted on the exterior of said camera adjacent said passage for spreading said liquid in a uniform layer of predetermined thickness between the photosensitive and second sheets of said film unit during withdrawal thereof from said camera, the last-mentioned means including a pair of substantially rigid members, and mounting means for operatively securing said members with parallel portions thereof in juxtaposition and predeterminedly spaced apart to provide a gap through which said film units is moved, said gap between said members comprising a throat for generating pressure in said liquid between the sheets of said film unit to distribute said liquid in a layer between said sheets during movement thereof through said throat between said members, said mounting means so mounting said rigid members on the exterior of said camera adjacent said passage that said film unit can be manually withdrawn substantially in a plane from said camera through said passage and said gap between said members, each of said members including a guide portion spaced from said gap on the exit side of said throat, said guide portions being so located with respect to one another and said gap as to provide a guide passage which is wider than said gap and is so located with respect to said gap as to guide said sheets through and beyond said throat in a plane substantially conincident with the aforementioned plane of Withdrawal from said camera.

2. Photographic aparatus for exposing and thereafter treating a photographic film unit including a photosensitive sheet, a second sheet superposable with said photosensitive sheet and means containing a processing liquid, said apparatus comprising, in combination, a camera for exposing the photosensitive sheet of a film unit and including a passage through which said film unit may be withdrawn from said camera following exposure therewithin and means mounted on the exterior of said camera adjacent said passage for spreading said liquid in a uniform layer of predetermined thickness between said photosensitive and second sheets during withdrawal of said film unit from said camera, the last-mentioned means including a pair of substantially straight rigid members, support means for mounting said members in operative position parallel to one another and spaced a predetermined distance apart to provide a gap through which said film unit is moved, said gap between said members comprising a throat for generating pressure in said liquid between the sheets of said film unit to distribute said liquid in a layer between said sheets during movement thereof through said throat between said members, support means so mounting said members on said camera adjacent said passage that said film unit can be manually withdrawn in a predetermined plane from said camera through said passage and said gap, said support means mounting said members for movement apart from one another to permit the movement of a film unit therebetween without causing pressure to be generated in the liquid carried by said film unit, each of said members including a guide section spaced from said gap on the exit side of said throat, said guide sections being so located with respect to one another and said gap as to guide said sheets through and beyond said gap substantially in said predetermined plane.

3. The apparatus of claim 2 wherein said rigid members, when in operative position, cooperate with said support means to form a substantially lighttight chamber exterior of said camera within which said film unit may be withdrawn through said passage from said camera and through said throat.

4. Photographic apparatus for exposing and thereafter treating a photographic film unit including a photosensitive sheet, a second sheet superposable with said photosensitive sheet and means containing a processing liquid, said apparatus comprising, in combination, a camera for exposing the photosensitive sheet of said film unit and including a passage through which said film unit may be withdrawn from said camera following exposure therewithin and means mounted on the exterior of said camera adjacent said passage for spreading said liquid in a uniform layer of predetermined thickness between said photosensitive and second sheets during withdrawal of said film unit from said camera, the last-mentioned means including a pair of members having substantially straight sections, support means mounting said members for movement to and from an operative position, and means for locating said members in an operative position wherein said straight sections are parallel with one another and spaced a predetermined distance apart to form a gap through which said film unit is moved, said gap between said members comprising a throat for generating pressure in said liquid between the sheets of said film unit to distribute said liquid in a layer between said sheets during movement thereof through said throat between said members, said support means so mounting said members on said camera adjacent said passage that said film unit can be manually withdrawn in substantially a predetermined plane from said camera through said passage and said gap, said members being pivotable from operative position adjacent one another to inoperative position apart from one another to permit the movement of a film unit therebetween without causing pressure to be created in the liquid carried by said film unit, said members including guide sections spaced from said gap and being so located with respect to one another and said gap when said members are in operative position as to provide a guide passage which is wider than said throat and is so located with respect to said throat as to guide said sheets through and beyond said throat in a plane substantially coincident with said predetermined plane.

5. The apparatus of claim 4 wherein said guide sections include divergently curved exit lips for imparting a curvature to said film unit during withdrawal of said film unit from said guide passage in a plane other than said predetermined plane.

6. The apparatus of. claim 4 wherein said members are pivotally mounted and cooperate, when in operative position, with said support means to form a substantially lighttight chamber exterior of said camera within which said film unit may be withdrawn through said passage from said camera and through said throat.

7. The apparatus of claim 4 wherein said guide sections include latch means for releasably retaining said members in operative position.

8. Photographic apparatus for exposing and thereafter treating a photographic film unit including a photosensitive sheet, a second sheet superposable with said photosensitive sheet and means containing a processing liquid, said apparatus comprising, in combination, a camera for exposing the photosensitive sheet of a film unit, said camera including a passage through which said film unit may be manually withdrawn following exposure, means for spreading said liquid in a uniform layer of predetermined thickness between the photosensitive and second sheets of said film unit during withdrawal thereof from said camera, the last-mentioned means being provided as a disposable element of said film unit capable of being detachably mounted on the exterior of said camera adjacent said passage and comprising a pair of substantially parallel rigid members and support means securing said members in juxtaposition and predeterminedly spaced apart to provide a gap through which said film unit is moved, said gap between said members comprising a throat for generating pressure in said liquid between the sheets of said film unit to distribute said liquid in a layer between said sheets during movement thereof through said throat between said members, said support means so mounting said rigid members on said camera adjacent said passage that said film unit can be manually withdrawn substantially in a plane from said camera through said passage and said gap between said members, and a pair of guide members mounted on said camera and spaced from said gap on the exit side of said throat, said guide members being so located with respect to one another and said gap as to provide a guide passage which is wider than said gap and is so located with respect to said gap as to guide said sheets through and beyond said throat in a plane substantially coincident with the aforementioned plane of withdrawal from said camera.

9. A photographic device for distributing a liquid in a uniform layer of predetermined thickness between two layers of photographic sheet material, said device being adapted to use in combination with photographic apparatus from which said sheet material is manually with drawn and comprising, in combination, a pair of substantially parallel rigid members secured together in juxtaposition and predeterminedly spaced apart to permit the movement of said sheet material therebetween, the gap between said members comprising a throat for generating pressure in a liquid between said layers of sheet material to distribute said liquid in a layer therebetween during movement of said sheet material through said throat between said members, each of said rigid members including a guide portion spaced from said gap on the exit side thereof, said guide portions being so located with respect to one another and said gap as to provide a guide passage which is wider than said gap and is so located with respect to said gap as to guide said sheet material therethrough in a single predetermined plane, and means for detachably mounting said device in operative position on the exterior of said photographic apparatus with said guide passage and said gap disposed in a plane which is coincident with the plane of withdrawal of said sheets from said camera through said gap. The combination, in a photographic film unit including a photosensitive sheet adapted to be exposed in a camera, a second sheet superposable with said photosensitive sheet and means containing a processing liquid, of a device for distributing said processing liquid between said sheets in a uniform layer of predetermined thickness during manual withdrawal of said sheets from said camera, said device being adapted to use in combination with said camera and comprising a pair of substantially rigid embers secured together in juxtaposed relation and having substantially parallel straight sections predeterminedly spaced apart to form a throat for generating pressure in said liquid between said sheets to distribute said liquid in a uniform layer during movement of said sheets through said throat between said members, and means for so mounting said rigid members on the exterior of said camera that said sheets can be withdrawn therefrom through said throat in a predetermined plane, eacn of said rigid members including a guide portion spaced from said throat on the exit side of said throat, said guide portions being so located with respect to one another as to provide a passage which is substantially wider than said throat and is so located with respect to said throat as to guide said sheets through and beyond said throat in a plane substantially coincident with said predetermined plane of withdrawal of said sheets from said camera into and through said gap.

11. Photographic apparatus for exposing and thereafter processing a photosensitive sheet by a liquid distributed in a layer between said exposed photosensitive sheet and another sheet superposed therewith, said apparatus comprising, in combination, a camera for exposing said photosensitive sheet, a pair of substantially rigid members secured in juxtaposition and predeterminedly spaced apart to provide a gap through which said sheets are movable, said gap between said members comprising a throat for generating pressure in a liquid between layers of said sheets to distribute said liquid in a layer during movement of said sheets through said throat between said members, means so mounting said rigid members on said camera that said sheets can be withdrawn therefrom through said gap in a predetermined plane, each of said rigid members including a guide portion spaced from said gap on the exit side of said throat, said guide portions being so located with respect to one another and said gap as to provide a passage located substantially in said plane and wider than said gap for guiding said sheets through and beyond said throat in said predetermined plane in which said sheets are drawn from said camera into and through said gap.

12. Photographic apparatus for exposing and thereafter treating a photographic film unit including a photosensitive sheet, a second sheet superposable with said photosensitive sheet and means containing a processing liquid, said apparatus comprising, in combination, a camera for exposing the photosensitive sheet of a film unit and means associated with said camera for spreading said liquid in a uniform layer of predetermined thickness between said photosensitive and second sheets during withdrawal thereof from said apparatus following exposure of said photosensitive sheet, the last-mentioned means including a pair of substantially parallel rigid members secured in juxtaposition and predeterrnincdly spaced apart to provide a gap therebetween through which said sheets are movable, said gap between said members comprising a throat for generating pressure in said liquid between the sheets of said film unit to distribute said liquid in a layer between said sheets during movement thereof through said throat between said memers, each of said members including a guide section spaced from said gap on the exit side of said throat, said guide sections being so located with respect to one another as to provide a passage which is substantially wider than said gap and is so positioned with respect to said gap as to guide said sheets through and beyond said throat in a single predetermined plane, and means mounting said rigid members in operative position on the exterior of said camera with said guide sections being so located with respect to said camera as to guide said sheets from said camera through and beyond said throat in said single predetermined plane.

13. Photographic apparatus for exposing and thereafter processing the photosensitive sheet of a film unit by a liquid distributed on said exposed photosensitive sheet and another sheet superposed therewith, said apparatus comprising, in combination, a camera, a pair of substantially parallel rigid members secured in juxtaposition and predeterminedly spaced apart to permit the movement of said film unit therebetween, the gap between said members comprising a throat for generating pressure in a liquid between the sheets of said film unit to distribute said liquid in a layer during movement of said sheets through said throat between said members, support means for detachably mounting said members on the exterior of said camera so that said film unit may be withdrawn from said camera substantially in a single predetermined plane through said gap, said rigid members and said support means being provided as disposable elements of said film unit, and a pair of guide members mounted on said camera and spaced from said rigid members on the exit side of said throat, said guide members being so located with respect to one another and said rigid members as to provide a passage which is wider than said gap and is located substantially in said prede termined plane for guiding said film unit from said camera through and beyond said gap substantially in said predetermined plane.

Reterences Cited in the file of this patent UNITED STATES PATENTS 2,483,389 Wolff Oct. 4, 1949 2,483,390 Gannon Oct. 4, 1949 

